Molded article extractor and method

ABSTRACT

A tire tread extractor used in the manufacture of treads includes a frame, a first nip roller rotatably associated with the frame, and a second nip roller rotatably associated with the frame. The first and second nip rollers are adapted to engage a tire tread at least partially resident in a mold. A driving mechanism associated with the first and/or second nip rollers operates to impart rotational motion thereto. The frame is configured for longitudinal movement along a substantial portion of a longitudinal length of the mold while maintaining the first and second nip rollers in a spaced relation to the mold.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is a divisional of copending U.S. patentapplication Ser. No. 13/281,587, filed Oct. 26, 2011, which isincorporated herein in its entirety by this reference.

FIELD OF THE DISCLOSURE

This disclosure relates to a device and method for removing moldedarticles from their molds and, more particularly, to the removal of avulcanized rubber molded article such as a tire tread from a mold of acuring press.

BACKGROUND OF THE DISCLOSURE

Molded articles may be formed when a preform of an article is placed ina mold for shaping. Removal of the article from the mold after a formingoperation is complete without causing damage to the molded article isoften carried out as a separate operation during the manufacturingprocess. Depending on the shape, placement and orientation of variousphysical features of the molded article, the removal of the article formthe mold may require special care to avoid tearing, breakage, or otherdamage.

In the field of tire manufacturing, a common molding operation includesvulcanizing a rubber composite material in a curing press. Curingpresses include molds that enclose a rubber composite preform to providepressure and heat cures the preform into a useable article, for example,a strip or belt of tire tread. Such tire treads are typically used intire retreading and other applications.

A typical curing press mold includes a mold plate that forms a cavity.One side of the cavity forms various depressions and ridges thatcorrespond to the desired tread pattern of the tire tread that willemerge therefrom. A plate or platen is placed over the mold cavity aftera tread preform has been loaded into the cavity. Pressure and heat areprovided by the press to force the preform to assume the shape of themold cavity and to cure the preform into vulcanized rubber.

In certain tread patterns such as those used for trucks or off-roadapplications, the tread lugs may have a substantial height relative tothe overall thickness of the tread, the tread sipes may be closelyspaced, the lugs may have negative draft angles, and other features thatcan create challenges when prying the finished tread from the mold.Given that rubber is an inherently elastic material, simply pulling oneend of the finished tire tread to remove the tread from the mold maypresent various challenges, including stretching of the tread, tearingor cracking of the tread, and other effects.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a partial view of a curing press in accordance with apreferred embodiment.

FIG. 2 is an outline view of a curing mold in accordance with apreferred embodiment.

FIG. 3 is a cross section of a curing mold and a finished tread inaccordance with a preferred embodiment.

FIG. 4 is an outline view of a tread extractor in accordance with apreferred embodiment.

FIG. 5 is a cross section of a tread extractor during a tread extractionoperation from a mold in accordance with a preferred embodiment.

FIG. 6 is a side view of a tread extraction operation in accordance witha preferred embodiment.

FIG. 7 is an alternative embodiment of a tread extractor in accordancewith a preferred embodiment.

FIG. 8 is another alternative embodiment of a tread extractor inaccordance with a preferred embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In one aspect, the disclosure describes a tire tread extractor used inthe manufacture of treads. The tire tread extractor includes a frame, afirst nip roller rotatably associated with the frame, and a second niproller rotatably associated with the frame. The first and second niprollers are adapted to engage a tire tread at least partially residentin a mold. A driving mechanism associated with the first and/or secondnip rollers operates to impart rotational motion thereto. The frame isconfigured for longitudinal movement along a substantial portion of alongitudinal length of the mold while maintaining the first and secondnip rollers in a spaced relation to the mold.

In another aspect, the disclosure describes a manufacturing assembly formanufacturing tire treads. The manufacturing assembly includes a moldingpress and a mold apparatus disposed within the molding press. The moldapparatus includes a mold having a molding cavity and a platen disposedto fit in relation to the molding cavity. The mold apparatus isconfigured to be capable of holding a tread preform within the moldingcavity in the forming of a tire tread. The platen and the mold areseparable to provide an opening therebetween. A tread extractorlongitudinally traverses the mold in spaced relation and includes aframe and a pair of nip rollers rotatably associated with the frame. Thepair of nip rollers is configured to be capable of engaging the tiretread while at least a portion of the tire tread remains in the moldingcavity.

In yet another aspect, the disclosure describes a method formanufacturing a tread. The method includes providing a frame capable ofmoving along a longitudinal length of a mold, and further providing apair of rotatable nip rollers relative to the frame. An end of the treadis freed from the mold and pinched between the nip rollers. Rotation ofat least one of the nip rollers is driven such that the tread is freedfrom the mold while advancing the frame and nip rollers along thelongitudinal length of the mold.

A curing press 100 from a side perspective is partially shown in FIG. 1.Although the curing press 100 may be part of a larger tread formingoperation that includes, for example, a composite preform buildingapparatus, a forming press, and other structures (not pictured). Thecuring press 100 includes top and bottom press blocks 102 and 104.Between the press blocks 102 and 104 are a plurality of mold assemblies106, each including two parts that come together to define an internalmolding cavity. In the illustration of FIG. 1, a mold 108 and a platen110 make up the mold assembly, but other configurations may be used. Forexample, what is referred to relative to FIG. 1 as a mold 108 may bepositioned in an inverted orientation in the press 100 such that a moldcavity is facing down. In such embodiment, the platen 110 would bepositioned below the mold 108 such that it fits over the mold cavity. Inthe description that follows, a particular orientation having the mold108 located beneath the plated 110 is discussed for illustration, but itshould be appreciated that the relative orientation of these twoelements may be in other orientations. Moreover, although six moldassemblies 106 are shown, a single assembly or a different number ofmold assemblies may be used. Each mold 108 forms a mold cavity 112 intowhich a preform is packed or loaded. Following the application ofpressure and heat to the closed mold assembly 106, a vulcanized tread114 can emerge. In other alternatives, the press may be configured toprovide continuous manufacture of the molded article or a tread in beltor other form.

The curing press 100 further includes linkages 116 that connect theparts of each mold assembly 106 to frame members or posts 118, whichinclude mechanisms (not shown) that can selectively move the variousparts of each mold assembly 106 vertically to enable the loading ofpreforms and the unloading of finished treads from each mold assembly106. Moreover, a robot arm 510 may be connected to a verticallyextending member 119, which extends between the posts 118 along a rail121. The robot arm 510 is configured to traverse the press 100 at leastalong the rail 121, which rail 121 extends along the length of the moldassemblies 106, and vertically along the member 119 relative to thecuring or molding press 100. The robot arm may alternatively beassociated with a grapple and a tread extractor device, as discussed inmore detail herein relative to FIG. 8. In a forming process for a tread114, a tread preform, which may be built by successively stacking layersof rubber with other materials such as thread, fabric, steel belts, wiremesh and the like, is loaded into a mold 108. Each mold 108 has ridgesand depressions formed therein that will shape and mold the lugs andsipes of a desired pattern in the emerging tread 114. The platen 110 isplaced in opposed relationship to the mold cavity 112 and a curingprocess ensues that vulcanizes the preform into the tread 114. The treadis thereafter detached and removed from the mold 108.

When forming the tread 114, the mold 108 imprints onto the preform apredetermined pattern of lugs and/or ribs. In reference to FIG. 2, theselugs are formed as depressions 202 in a bottom surface 204 of the mold108, which are separated by sipe blades or ridges 203. The mold 108forms an internal cavity 206 that is open from the top and surrounded bythe bottom surface 204 and walls 210 that extend around the perimeter ofthe cavity 206. Although a mold configured to form a single tread stripis shown, the mold may include two or more additional cavities extendingparallel to one another and configured to form two or more tread stripsfrom a single preform. In the illustrated embodiment, the single-cavitymold 108 has a generally elongate rectangular shape that extends alongan axis 212. The mold 108 further includes two tracks or ledges 214extending along its sides, generally parallel to the axis 212. Eachledge 214 is disposed on one side of the mold 108 and includes a track216 that extends generally parallel to a top edge 218 of the sideportion of the wall 210 at an offset vertical distance 220 therefrom.Although the ledges 214 are shown to have a length that is about equalto the overall length of the mold 108 in FIG. 2, the ledges 214 canextend past the ends of the mold 108, as shown in FIG. 1.

A cross section of the mold assembly 106 during a molding operationphase is shown in FIG. 3. In this illustration, the mold assembly 106 isshown opened following a molding and curing operation for the tread 114.The top mold or platen 110 includes a bottom surface 222 that forms thetop or inner surface 224 of the tread 114. The lateral surfaces 226 andthe outer or tread surface 228 of the tread 114 are formed,respectively, by the side walls 210 and bottom surface 204 of the mold108. Flash 227 may remain on the tread 114 along the interface betweenthe platen 110 and the mold 108. A plurality of lugs 230 arranged alongthe tread surface 228 are formed by the corresponding lug depressions202.

As may be seen in the cross section of FIG. 3, certain tread patternsmay include small or even negative draft angles formed in the surfacesaround the sides of the lugs 230. Draft angle denotes the resultingangle formed by mold surfaces relative to the direction of removal ofthe molded article from the mold. Accordingly, positive draft angles aredisposed such that the removal of the molded article is facilitated,whereas negative draft angles are disposed such that at least somedeformation of the molded article is required to remove it from themold. In the cross section of FIG. 3, the lugs 230 have negative draftangles on their side surfaces 232, which have been exaggerated for thesake of illustration. As can be appreciated, certain portions of thelugs would have to elastically deform when removing the tread 114 fromthe mold 108. Depending on the amount of material subject to suchdeformation during removal of the tread 114 from the mold 108, the forcerequired to remove the tread 114 from the mold may increase, as will thepotential for damage to the tread 114 due to cracking or tearing aspreviously described.

An outline of a nip roller tread extractor 300, which is suitable forremoving treads from curing molds or presses and especially those treadshaving features that can increase the force required to remove the treadfrom the mold without causing damage to the tread, is shown in FIG. 4.In the illustrated embodiment, the extractor 300 includes a frame 302that rotatably supports a set of nip rollers 304 that are adapted to becapable of engaging a molded article at least partially resident in amold, for example, a tread. A first nip roller 306 is mounted to a firstaxle 308 that is supported by the frame 302 such that the first niproller 306 can rotate relative thereto about a centerline 310 of thefirst axle 308. The rotation of the first nip roller 306 relative to theframe 302 about the centerline 310 may be accomplished at an interfacebetween the first nip roller 306 and the first axle 308 and/or aninterface between the first axle 308 and the frame 302. In theillustrated embodiment, the first nip roller 306 is rigidly connected tothe first axle 308 such that rotation of both components can be providedat the interface between the first axle 308 and the frame 302. In thisway, the driving force that can move the frame 302 relative to a moldduring an extraction process may be accomplished by pulling the framealong the mold either by a pulling or tensile force applied to themolded article via the first nip roller and/or a driving force appliedthrough the first axle 308 to wheels 312 that engage the mold.

The first axle 308 extends past either side of the frame 302 andincludes a mold engagement mechanism (e.g., wheels 312) rotatablydisposed on the free ends of the first axle 308. In the illustratedembodiments, both wheels 312 have the same diameter and are disposed tofreely rotate relative to the first axle 308. Each wheel 312 is disposedon the first axle 308 such that the frame 302 and first nip roller 306are located between the wheels 312, but other configurations may beused. In an alternative embodiment, for example, the wheels 312 may beomitted or the diameter of the first axle 308 may be increased atvarious segments thereof such as its ends to replace the wheels. In analternative embodiment where the extractor 300 is powered along themold, the wheels 312 of the mold engagement mechanism may be replaced bypinion gears (not pictured) that engage a rack gear formed along thelongitudinal length of the mold to provide traction for a driving forcethat moves the frame relative to the mold. In such embodiments, the rackand pinion drive are mentioned as an illustrative but not limitingexample of a driving mechanism, but other driving mechanisms may beused.

A second nip roller 314 is mounted to a second axle 316 that is slidablyconnected to the frame 302 via sliding blocks 318. Although a slidingarrangement is shown, the second nip roller 314 may be connected to anarm that is pivotally connected to the frame 302 such that rotation ofthe arm relative to the frame can adjust or change the distance betweenthe first and second rollers 306 and 314. Moreover, a spring or otherresilient element may operate to impart a force tending to push the tworollers together such that a pinching force applied to the tread betweenthe rollers may be augmented. In the illustrated embodiment, the secondnip roller 314 is configured to rotate relative to the frame 302 about acenterline 320 of the second axle 316, and translate in a directiontowards or away from the first nip roller 306 by motion of the slidingblocks 318 relative to the frame 302. More particularly, a distance, T,between the first and second rollers 306 and 314 can be adjusted whenthe sliding blocks 318 are moved relative to the frame 302. Such motion,in the illustrated embodiment, is accomplished by providing a pair ofparallel frame rails 322 that slidingly engage therebetween recesses 324formed in the sides of each sliding block 318. An adjustment screw 326or other mechanism can move the sliding blocks 318 and thus the secondnip roller 314 relative to the frame 302 such that the distance T can beadjusted to sufficiently pinch objects between the second and first niprollers 314 and 306 having variable thicknesses. It should beappreciated that although one configuration that allows for pinching ofobjects of various thickness is illustrated herein, other configurationscan be used to equivalently selectively vary the distance between thenip rollers 306 and 314. The second nip roller 314 may also be rotatablydriven as an alternative or compliment to the other driving mechanismsas described herein.

The extractor 300 also includes an optional third wheel 328 that isrotatably mounted onto the end of a leading bar 330 that is pivotallyconnected at its other end 332 to the frame 302. The third wheel 328,along with the wheels 312 connected to the first axle 308 as previouslydescribed, provides a stable stance and orientation of the extractor 300relative to the rolling surfaces of the wheels 312 and 328, as is shownmore particularly to the section views of FIGS. 5 and 6. Moreover, theoptional third wheel 328 may be steerable or otherwise adjustable toensure that the extractor 300 travels along a path that is parallel tothe axis 212 of the mold 108 (FIG. 2).

FIG. 5 is a cross section from a front perspective and FIG. 6 is a crosssection from a side perspective of the tread extractor 300 in use duringremoval of a tread 114 from the mold 108. As shown in FIG. 5, the wheels312 of the extractor 300 ride on the tracks 216 of the mold 108 when theextractor 300 is operating to remove the tread 114 from the mold cavity206. When flash 227 (see FIG. 3) is present on the tread 114, the wheels312 are advantageously placed in contact with the mold 108 beneath anyflash that may be present. As best shown in FIG. 6, the third wheel 328rides on the top or inner surface 224 of the tread 114 to providestability to the extractor 300 as well as to define a predeterminedorientation of the nip rollers 306 and 314 relative to the mold 108.

In the illustrated embodiment, the nip of the rollers 314 and 306 may beconfigured to apply a tensile force to the tread 114 in addition to thelifting force caused by the tread passing through the offset nip of therollers 314 and 306. The combination of the forces may be illustrated asa combined force in a direction, A, as depicted in FIG. 6. The resultingcombined force, A, may result in an axial force component being appliedin a direction, B, along the mold cavity 206, and in a normal forcecomponent being applied in a direction, C, normal to the mold cavity206. For illustration purposes, the normal force component may operateto lift the tread 114 away from the mold 108, while the axial forcecomponent may operate to locally stretch the tread, thus providing, atleast partially, a local deformation along a segment 334 of the tread114. It is also possible that there is a normal force component thatoperates to locally stretch the tread.

The segment 334 of the tread 114 includes a freed portion of the tiretread that has not yet reached the nip of the rollers 306 and 314, incontrast to the portion of the tread 114 that is still resident in themold 108. This deformation of the segment 334 can further aid to releasethe tread 114 from the mold 108 as previously described. The selectionof an appropriate angle of extraction (e.g., extraction angle betweenvectors A and B as depicted in FIG. 6) of the tread 114 from the moldcavity 206, which can affect the relative magnitude between the axialand normal force components, can depend on various factors such as thethickness of the tread 114, the height of the lugs 230 (FIG. 3), thelocation, orientation and size of the negative draft angle portions ofthe tread pattern, if any, the composition and makeup of the tread 114and other factors. The extraction angle may be affected by a number ofoperational parameters including the orientation of the rollers to thetread where there is provided an inclination which may be considered asa line connecting the two center-points of a given cross section of thenip rollers, which inclination is configured to lean either in theleading or following direction from vertical relative to the directionof motion of the extractor along the tread strip. When releasing thetread strip, in one embodiment, the tread 114 is manually released fromone end of the mold 108 and fed in between the nip rollers 306 and 314where the nip rollers are thereafter brought into engagement with thetread 114 establishing the forces explained herein. The feeding of thetread between the rollers may be accomplished manually. Depending on theinclination of the rollers, the tread strip may wrap along a circularsegment of a cross section of the first roller 306 in a clockwise orcounterclockwise manner, which may increase a desired frictionalretention force between the rollers and the tread strip. The extractionangle A relative to the mold and angle B, may range from acute (e.g., asshown in FIG. 6) to obtuse (e.g., where roller 306 leads the extractionpoint), including a perpendicular extraction angle.

Returning now to FIG. 5, the traction between the nip rollers 306 and314 can be adjusted to suit the particular parameters of eachapplication. As can be appreciated, the magnitude of the force from therollers that stretches the tread 114 as previously described can beincreased with improved traction between the tread and the rollers.Various roller configurations can be used for this purpose such assplined rollers, which can include various projections on one rollerthat cooperate with slots in the other roller, or knurled rollers, whichcan include any type of small ridges or grooves on the surface of one orboth rollers arranged randomly or according to a pattern. In theillustrated embodiment, the bottom nip roller 306 is knurled havingridges 336 arranged in a diamond pattern. The ridges 336 can provide animproved grip on the lugs 230 of the tread pattern on the tread 114 ascompared to the grip provided by smooth rollers. The top nip roller 314,which contacts the top or inner surface 224 of the tread 114, is alsoknurled having ridges 338 that extend parallel to one another and to thesecond centerline 320.

The embodiment for the extractor 300 illustrated in FIG. 5 furtherincludes a drive system 340 that powers the rotation of the nip rollers306 and 314. Although the drive system 340 is capable of driving bothrollers 306 and 314 with a single motor 342, more than one motor may beused to individually power each roller. When the rollers 306 and 314 arepowered, they operate to move or pull the extractor along the mold 108while the tread 114 is removed. The points of rolling contact betweenthe extractor 300 and the mold 108 (the wheels 312 and 328), are freespinning in the illustrated embodiment but may be configured for poweredmotion in alternative embodiments. As an alternative, the removal of thetread may proceed by moving the nip rollers along the mold in thelongitudinal direction while maintaining the rollers in a fixed relationto mold. In such circumstances, the offset of the nip rollers willimpart a lifting force to the tread as the nip rollers pass along thelength of the tread.

In the illustrated drive system 340, the drive motor 342 has an outputshaft 344 connected to a drive pulley 346. The drive pulley 346 engagesa drive belt 348 that transfers the rotation of the drive pulley 346 toa first axle driven pulley 350. The first axle driven pulley 350 isconnected to the first axle 308 such that rotation of the output shaft344 is transferred to the first nip roller 306. In an embodiment whereboth rollers are driven, the first axle 308 may include a second rollerdriver pulley 352 that is rotatably connected to an second axle drivenpulley 354 by a transfer belt 356. In this way, rotation of the outputshaft 344 is optionally transferred to both the second and first axles308 and 316 such that the second and first nip rollers 306 and 314 canrotate at substantially the same angular speed. Of course, although abelt-driven system is shown and described herein, the transfer of motionor powering of the nip rollers or engagement mechanism associated withthe mold (e.g., wheels 312, etc.) can be accomplished by any other knownmotion transfer means such as chains, gears, a gearbox, individualmotors to drive each roller, and other known devices.

As described thus far, the powered rotation of the nip rollers 306 and314 of the extractor 300 can pull the extractor 300 along a tread 114while the tread is freed from a mold. Driving the rotation of at leastone of the nip rollers accomplishes the freeing of the tread from themold while advancing the frame and nip rollers along the longitudinallength of the mold. In one embodiment, a freeing process of the tread114 from the mold 108 can begin by placement of the extractor 300adjacent one end of the mold 108. One end of the tread 114 can be freedfrom the mold 108 either manually or by use of a tool inserted betweenthe mold 108 and the tread 114. The free end of the tire tread 114 canthen be fed into the nip of the rollers 306 and 314 and thus engagedwith the extractor. Thereafter, the extractor 300 may begin the poweredrotation of the nip rollers 306 and 314 that will cause the extractor300 to be pulled along the mold 108. As the extractor 300 travels alongthe length of the mold 108, it will leave behind a freed section oftread 114, which may simply lie over the mold cavity 206. When removingthe freed tread 114 from the mold 108, an arm 358 (also shown in FIG. 1)may be used to grab the freed tread 114 that sits on top of the mold 108and remove it.

As shown, the arm 358 includes clamping elements 360 configured toselectively engage one end of the tread 114. After the tread 114 hasbeen released from the mold 108, the arm 358 with the end of the tread114 clamped between the elements 360 may move in one direction or theother relative to the mold 108 to remove the released tread 114. In oneembodiment as shown, for example, in FIG. 1, the arm 358 may move in anopposite direction than the direction of travel of the extractor 300during an extraction process after the entire tread 114 has been freedfrom the mold 108. In alternative embodiments, the arm 358 may followthe extractor 300 and may even be connected to the extractor 300, aswill be hereinafter described.

FIG. 7 is a side view in partial cross section of an alternativeembodiment for an extractor 400 in accordance with the disclosure. Theextractor 400 includes a body 402 that includes a set of nip rollers 404having a second roller 406 and a first roller 408. The extractor 400further includes a set of wheels 410 (three shown) that ride alongridges formed on the side of the first mold 108 as previously discussed.A grapple arm 412 is connected or otherwise associated with the body 402and includes two fingers 414 configured to engage and retain the end ofthe tread 114 that is freed first from the mold 108. In this embodiment,as the extractor 400 frees the tread 114 from the mold 108, the grapplearm 412 retains the end of the tread 114 and pulls it along the mold 108as the extractor moves, as shown in FIG. 7, in a direction from right toleft. In this way, the freeing and removal of the tread 114 from themold 108 can be accomplished in a single operation with a single pass ofthe extractor 400 over the mold 108.

As in the previous embodiment, the extractor 400 features structuresconfigured to provide powered rotation to the nip rollers 404, whichoperate to stretch a segment of the tread 114 for easy removal from themold 108. The distance between the rollers 404 as well as the angle ofthe application of the removal force applied to free the tread 114 fromthe mold 108 can be adjusted to suit the particular tread being freed.After the tread has been removed from the mold, the extractor 400 may bereturned to a starting position on the side of the mold that it beganits removal procedure, or may alternatively remain on side of the moldwhere the removal was completed and be reversed to remove the now freedtread strip from the mold 108. The reversal of the extractor in such aconfiguration may be accomplished by reversing the rotation of one ormore prime movers operating to turn the rollers.

An additional alternative embodiment of an extractor 500 is shown inFIG. 8. As shown, the extractor 500 is substantially similar inoperation to the extractor 400, but instead of having wheels 410engaging the mold 108, the extractor 500 is connected to a robot arm510. As previously described relative to FIG. 1, the robot arm 510 isconfigured to traverse the length of the mold 108 at a predetermineddistance therefrom, such that removal of the strip of tread 114 isfacilitated without direct contact between the extractor 500 and a metalsurface of the mold 108. Other elements and features of the extractor500 that are the same or similar to corresponding elements and featuresof the extractor 400 previously described are denoted by the samereference numerals as previously used for simplicity.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1-14. (canceled)
 15. A manufacturing assembly capable of manufacturingtire treads, comprising: a molding press; a mold apparatus disposedwithin the molding press, the mold apparatus including a mold having amolding cavity and a platen disposed in opposed relationship to themolding cavity, wherein the mold apparatus is configured to be capableof holding a tread preform within the molding cavity in the forming of atire tread and wherein the platen and the mold are separable to providean opening therebetween; a tread extractor longitudinally traversing themold in spaced relation, the tread extractor comprising: a frame; a pairof nip rollers rotatably associated with the frame, wherein the pair ofnip rollers is configured to be capable of engaging the tire tread whileat least a portion of the tire tread remains in the molding cavity. 16.The manufacturing assembly of claim 15, further comprising a trackextending at least along substantially an entire length of the mold,wherein the tread extractor slidably engages the track while traversingthe mold.
 17. The manufacturing assembly of claim 15, wherein the treadextractor further comprises a driving mechanism associated with the niprollers, the driving mechanism operating to provide powered rotation toat least one of the pair of nip rollers.
 18. The manufacturing assemblyof claim 17, further comprising a mold engagement mechanism adapted toprovide a rolling contact between the frame and at least one of asurface of the mold and a surface of the tire tread disposed in themold.
 19. The manufacturing assembly of claim 15, wherein the pair ofnip rollers includes first and second nip rollers disposed at an offsetvertical distance relative to one another such that the tire tread isplaced under tensile force at an extraction angle relative to the mold.20. The manufacturing assembly of claim 19, wherein the extraction angleis an acute angle.
 21. The manufacturing assembly of claim 19, whereinthe extraction angle is an obtuse angle.
 22. The manufacturing assemblyof claim 18, wherein the mold engagement mechanism comprises at leastthree wheels adapted to engage at least one of a surface of the mold anda surface of the tire tread.
 23. The manufacturing assembly of claim 22,wherein two of the at least three wheels engage a track on either sideof the mold and are rotatably driven in association with an axleextending along a centerline of one of the pair of nip rollers.
 24. Themanufacturing assembly of claim 23, wherein a third of the at leastthree wheels is connected to an end of an inclination arm cantileveredaway from the frame at an inclination angle, and wherein the third ofthe at least three wheels is adapted to engage an inner surface of thetire tread.
 25. The manufacturing assembly of claim 15, wherein thetread extractor further comprises: a mold engagement mechanism adaptedto provide a rolling contact between the frame and at least one trackassociated with the mold; and a driving mechanism associated with themold engagement mechanism, the driving mechanism contacting at least onetrack associated with the mold and being capable of impartinglongitudinal movement to the frame along the at least one track.
 26. Themanufacturing assembly of claim 15, wherein the tread extractor isadapted to stretch at least a freed portion of the tire tread away fromthe mold, the freed portion of the tire tread extending between aportion of the tire tread engaged with the mold and a nip point betweenthe pair of nip rollers, such that a remaining portion of the tire treadthat has already passed through the nip rollers is substantiallyunstretched.
 27. The manufacturing assembly of claim 26, furthercomprising a grapple arm configured to engage and retain a freed end ofthe tire tread such that a portion of the tire tread that has beenremoved from the mold can be withdrawn from the opening between the moldand the platen after the tread extractor has completed a pass oversubstantially an entire length of the mold.
 28. The manufacturingassembly of claim 17, wherein the driving mechanism is furtherconfigured to provide a powered reverse rotation to at least one of thepair of nip rollers such that the tire tread can be withdrawn from theopening between the mold and the platen after the tire tread has beenremoved from the mold.
 29. The manufacturing assembly of claim 15,further comprising a robot arm connected to the frame and slidablyassociated with the molding press such that the frame, carried by therobot arm, traverses, in spaced relation, the substantial portion of thelongitudinal length of the mold. 30-31. (canceled)